Dynamoelectric machine



June 2, 1942. w. HETER DYNAMO-ELECTRIC MACHINE Filed July 19, 1940 2Sheets-Sheet l Inventor- Wylie Pieter",

His Attorney.

June 2, 1942. w HETER DYNAMO-ELECTRIC MACHINE Filed July 19, 1940 2SheetsSheet 2 Inventor ie Hater;

I W I .33

His Attorneg Patented June 2, 1942 DYNAMOELECTRIC MACHINE Wylie Heter,Scotia, N. Y., assignor to General Electric Company, a. corporation ofNew York Application July 19, 1940, Serial No. 346,378

8 Claims.

My invention relates to improvements in dynamo-electric machines.

An object of my invention is to provide an improved ventilating systemfor dynamo-electric machines.

Another object of my invention is to provide an improved cooling mediumimpeller particularly adapted for use in dynamo-electric machineventilating systems.

Further objects and advantages of my invention will become apparent andmy invention will be better understood from the following descriptionreferring to the accompanying drawings, and the features of noveltywhich characterize my invention will be pointed out with particularityin the claims annexed to and forming part of this specification.

In the drawings, Fig. 1 illustrates a dynamoelectric machine and itsassociated equipment providing my improved ventilating system; Fig.

.2 is a side elevational view, partly in section, of

a dynamo-electric machine showing the details of my improved coolingmedium impeller and asl; and Fig. 3 is an end view, partly broken away,

of the machine shown in Fig. 2.

Referring to the drawings, I have shown a dyname-electric machine of thecommutator type which is adapted to be cooled by a substantially closedventilating system. With this type of equipment, it is often found thatthe commutator temperatures limit the capacity of the machine so that vit is desirable that the flow of ventilating medium should first passover the commutator before coming in contact with other parts of themachine. Such an arrangement, however, has been found undesirable withcommutator machines. particularly if carbon brushe are used, as thewearing of the brushes produces carbon dust which then is drawn into themachine and tends to collect on the machine parts and decrease theefliciency of\heat transfer from the other parts of the machine, thusdecreasing the efficiency of the ventilating system.

The illustrated dynamoelectric machine is.

which i adapted to react electrodynamically with the stationary member fthe machine and includes an armature provided with a laminated core l5of magnetic material mounted upon a shaft l6 supported at one end by a.pedestal bearing l1 and adapted to be coupled to another shaft at theother end by a coupling flange 18 formed on the shaft 16. The rotatablemember is provided with an armature winding l9 ar--' ranged in slotsformed in the laminated core l5 and connecting leads 20 extend from thewinding to a commutator provided with commutator bars 2| having riserelements 22 to which the connecting leads 20 are electrically connected.The commutator bars 2| are secured together by a clamping flange 23 anda mounting ring 24 secured to the shaft. A plurality of carbon brushes25 is adapted to collect electric current from the commutator andthesebrushes are arranged in brush holders 26 to which they are electri-,.

cally connected by leads 21. The brush holders 26 are supported byinsulating mountings 28 secured to a mounting plate 29 which form aclosure for a ventilating medium exhaust casing 30 mounted on thestationary magnet frame I0.

In order to ventilate the machine, a double fan including a web 3| ismounted directly upon the commutator risers 22 and secured thereto by ashrink fit about a, ring 32 of insulating material. In order to insureagainst the deposit of carbon from the brushes 25 on the machineelements, the fan is provided with ventilating medium impeller bladeelements 33 on the side thereof towards the commutator and other fanblade elements 34 on the side of the web 3i towards the machinewindings. The impeller blades 34 are adapted to draw ventilating mediumthrough the machine about the pale pieces I3 and the field excitingwindings I4 and over the armature winding I9 and through axiallyextending passages 35 in the shaft l6 extendingtherethrough from eachend and communicating with radially extending ventilating passages 36formed in the laminated core l5. This ventilating medium is exhausted bythe impeller blades 34 into the exhaust casing 30 without passing overthe commutator elements 2t so that only clean air is drawn through thedynamo-electric machine rotatable member and over the stationary memberof the machine. In order to cool the commutator, the armature windingleads 20 are arranged to extend through the commutator risers 22 andextend beyond these risers in the form of ventilating medium impellerblades 31 which are adapted to draw air over the commutator. An annularplate 38 of insulating material is secured to the mounting rings 29 andextends to closely adjacent the outer periphery of the commutator nearthe armature lead projections 31 for directing the ventilating mediumflow over the commutator towards these lead projections. This insulatingplate also provides an added protection when it is desired to change orexamine the brushes while the machine is operating. The ventilatingmedium flow over the commuta tor which is created by the armature leadprojection 31 is assisted by the impeller blades 33 which exhaust thisventilating medium into the exhaust casin 30, thereby insuring aseparate flow of ventilating medium overthe commutator and through thestationary and rotatable members of the machine. All of the ventilatingmedium which cools the dynamo-electric machine is exhausted through thecasing at the lower end 39 thereof, and, as shown in Fig. 1, passesthrough an air filter ID of any suitable type from which it is conductedthrough a ventilating medium cooler 4| and returned through an opening42 in the supporting platform structure I2 to the enclosing casingformed by walls 43, 44, and 45 about the dynamo-electric machine. Theflow of the cooling medium is indicated by arrows in Figs. 1 and 2 toillustrate more clearly how the cleaned and cooled ventilating medium isadapted to flow through the machine without drawing into the machine anyof the carbon brush dust.

While I have illustrated and described a particular embodiment of myinvention, modifica tions thereof will occure to those skilled in theart. I desire it to be understood, therefore, that my invention is notto be limited to the particular arrangement disclosed, and I intend inthe appended claims to cover all modifications which do not depart fromthe spirit and scope of my invention.

-What I claim as new and desire to secure by Letters Patent of theUnited States is:

l. A dynamo-electric machine having a stationary member and a rotatablemember provided with a winding and a commutator having risers forconnecting said .winding thereto, a double fan mounted on saidcommutator risers, means for insulating said tan from said risers, andmeans including said fan having ventilating medium propelling elementson the side thereof towards said commutator and on the side thereoftowards said winding for drawing a separate flow of ventilating mediumthrough said stationary and rotatable members and over. said commutator.

2.-A dynamo-electric machine having a stationary member and a rotatablemember provided with a winding and a commutator having risers forconnecting said winding thereto, said winding having connecting leadselectrically connected to said commutator risers and projectingtherethrough towards said commutator forming impeller blades extendingover said commutator adapted to circulate ventilating medium over saidcommutator, and means including an insulating plate arranged to extendto closely adjacent the outer periphery of said commutator for directingthe ventilating medium flow over the commutator towards said leadprojections.

vided with a winding and a commutator having risers for connecting saidwinding thereto, said winding having connecting leads electricallyconnected to said commutator risers and projecting therethrough towardssaid commutator forming impeller blades adapted to circulate ventilatingmedium over said commutator, a double fan mounted on said commutatorrisers, means for insulating said fan from said risers, means includingsaid double fan for drawing. a separate flow of ventilating mediumthrough said stationary and rotatable members and over said commutator.

5. A dynamo-electric machine having a stationary member and a rotatablemember provided with a winding and a commutator having risers forconnecting said winding thereto, said winding having connecting leadselectrically connected to said commutator risers and projectingtherethrough towards said commutator forming impeller blades adapted tocirculate ventilating medium over said commutator, a ventilating mediumexhaust casing, a double fan mounted on said commutator risers, meansfor insulating said fan from said risers, means including said doublefan for drawing a separate flow. of ventilating medium through saidstationary and rotatable members and over said commutator and exhaustingthe ventilating medium into said exhaust casing, means communicatingwith said exhaust casing for cooling and cleaning the ventilatingmedium, and means for conducting the,

cooled and cleaned ventilating medium to said dynamo-electric machine.

6. A dynamorelectric machine having a sta-- tionary member and arotatable memberprovided with a winding and a commutator having risersfor connecting said winding thereto, said winding having connectingleads electrically connected to said commutator risers and projectingtherethrough towards said commutator forming impeller blades adapted tocirculate ventilating medium over said commutator, means including aninsulating plate arranged to extend to closely adjacent the outerperiphery of said commutator for directing the ventilating medium flowover the commutator towards said lead projections,

3. A dynamo-electric machine having a stav, tionary member and arotatable member provided with a winding and a commutator having risersfor connecting said winding thereto, a

ventilating medium exhaust casing, a double fan mounted on saidcommutator risers, means for insulating said fan from said risers,'meansincluding said fan having ventilating medium promeans including a doublefan mounted on said commutator risers and provided with ventilatingmedium propelling elements on the side thereof towards said commutatorand on the side thereof towards said winding for cooperating with saidprojecting lead impeller blades in drawing a separate flow of saidmedium over said commutator andthrough said stationary and rotatablemembers, and means for insulating said fan from said risers;

7. A dynamo-electric machine having a stationary member and a rotatablemember provided with a winding and a commutator having risers forconnecting said windin'g thereto, said winding having connectingleadselectrically connected to said commutator risers and projectingtherethrough towards said commutator forming impeller blades adapted tocirculate ventilating medium over said commutator, means including aninsulating plate arranged to extend to closely adjacent the outerperiphery of said commutator for directing the ventilating medium flowover the commutator towards said lead projections, a ventilating mediumexhaust casing, a double Ian mounted on said commutator risers, meansfor insulating said fanufrom said risers, means including said fanhaving ventilating medium propelling elements on the side thereoftowards said commutator and on the side thereof towards said winding fordrawing a separate flow of said medium through said stationary androtatable members and over said commutator and exhausting theventilating medium into an exhaust casing, means communicating with saidexhaust casing for cooling the ventilating medium, means for cleaningthe ventilating medium, and means for conducting the cooled and cleanedventilating medium to said dynamo-electric machine.

8. A ventilating medium impeller for a dynamo-electric machine providedwith a commutator comprising connecting leads from the dynamoelectricmachine rotatable member winding having portions extending through riserelements 01' said commutator and from the other side over saidcommutator, said extending portions forming impeller blades adapted tocirculate ventiiating medium over said commutator.

WYLIE HETER.

